JPH0474488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for press-fitting and sinking a precast concrete multilayer caisson as a base for propulsion work of pipe facilities, mainly sewerage.

The purpose is to rationalize and simplify the underground installation work of caissons (shafts), shorten the construction period, and reduce construction costs.

Conventionally, this type of shaft was built by driving steel sheet piles in parallel into the soil in a certain area, excavating and discharging the internal soil, then pouring concrete at the bottom, and then cutting out a portion of the steel sheet piles before starting. A dual-reaching tunnel entrance was created, and the pipes to be suspended into the shaft were installed sequentially from the starting tunnel entrance.
Alternatively, the front end of the propulsion culvert is received, and after completion of the propulsion installation of the culvert, a rectangular or round manhole is formed in the shaft with cast-in-place concrete, backfilled with earth and sand, and the steel sheet piles are removed. Therefore, there were problems in that the construction period was long and the required construction costs were large.

The present invention is an improvement on this, and its configuration is such that four earth anchors are inserted deep into the ground from the four corner points, and a cutting edge block formed in a square frame shape in plan view is suspended inside each of the earth anchors. The cutting edge block is pressed into the ground by multi-point pushing using a plurality of hydraulic jacks provided under the upper pressure plate that is fixed to each of the earth anchors, and the cooperation of excavating and discharging the earth and sand in the cutting edge block. , at the point where the cutting edge block is press-fitted to a certain depth, remove the hydraulic jack,
The lower concrete block is placed and connected on the cutting edge block, the hydraulic jacks are reattached, and the vertically divided joint surfaces are formed on the cutting edge block by repeating multi-point pushing and excavation and removal. A lower concrete block, an intermediate concrete block, and an upper concrete block, which are formed so as to be shifted from each other in a staggered manner between adjacent blocks, are sequentially mounted and press-fitted to a predetermined depth.

With the above configuration, there are four precast concrete multilayer caisson cutting blocks or upper concrete blocks that are inserted deep into the soil from the four corner points and serve as bases for laying propulsion pipes that are successively press-fitted and sunk into the ground. Using the earth anchor as the stopping point, the four sides are pressed evenly by multi-point pushing using a plurality of hydraulic jacks, so it can be press-fitted and sunk efficiently while maintaining the horizontal position.

Furthermore, the lower and upper concrete blocks can be manufactured using precast products to correspond to any shaft depth and shape. It is possible to improve the quality of concrete and prevent variations in strength. Since blocks are assembled using the building block method to suit the site, construction can be carried out quickly. By shortening the construction period, traffic routes can be opened quickly and traffic disturbances can be reduced.

Hereinafter, the present invention will be explained in detail based on the drawings.

The earth anchors 12 are driven deep into the soil from the four corners of the ground 11 where the precast concrete multilayer caisson is to be press-fitted.
The lower end is hardened by injecting grout 13, and first, the cutting edge block 14 formed into a rectangular frame shape in plan view is suspended on the ground 11 between the earth anchors 12, and the pressurizing H-shaped steel 15 is placed between the parallel earth anchors 12.
Place two pieces in parallel. 16 is the blade mouth block 1
4 and the H-shaped steel 15. A lower pressure plate 17 is mounted on both ends of the H-shaped steel 15 through the earth anchors 12, a set of two hydraulic jacks 18 are placed on the pressure plate 17, and an upper pressure plate 19 is mounted on the hydraulic jacks 18. is placed and tightened by a cone hydraulic chuck 20 that is inserted into the earth anchor 12.

The blade block 14 has a tapered tip on the inside, and a metal plate 14a is attached to the tip.
Reference numeral 4b indicates an upper anchor line, and 14c indicates a lower anchor line. The upper anchor line 14b has an opening formed by screwing a coupler 26 onto a threaded portion 14d, and is provided with a recess 14e. Further, a groove 14f is provided on the outer surface of the intermediate portion of the blade block 14, into which a water-stopping rubber ring 14g is fitted so as to partially protrude. Note that 14i is a flat bar, and 14j is a stop groove for the vertical PC steel bar 23 provided at the top of each inner corner.

When each hydraulic jack 18 is operated while excavating and discharging the soil inside the cutting edge block 14, the pressurizing H
By pressing the mold steel 15, the cutting edge block 14 is pressed at multiple points and press-fitted into the soil. At this time, when the cutting edge block 14 is tilted to one side, the operating pressure between the hydraulic jacks 18 is adjusted to return the cutting edge block 14 to the horizontal position, and thereafter the cutting edge block 14 is press-fitted while maintaining the horizontal position. At the point where the cutting edge block 14 is press-fitted to a certain depth, the press-fitting mechanism and the bottom plate 16 above the pressurizing H-shaped steel 15 are removed,
The lower concrete block 21a is placed on the cutting edge block 14 and the vertical sheath 2 is installed vertically at the four corners.
2, the vertical PC steel body 23 is inserted and the lower end is tightened by tightening the nut 23b at the stop groove 14j provided at the upper part of the inner corner of the cutting edge block 14. This lower concrete block 21a is formed smaller in plan view than the cutting edge block 14, and therefore the lower concrete block 21a
A gap 24 is left between the earth wall 11a and the earth wall 11a by press-fitting the blade block 14.

The lower concrete block 21a is divided into four vertically divided bodies 21-1, 21- as shown in FIG.
2, 21-3, and 21-4, they are assembled on the ground before being placed on the cutting edge block 14. A lateral sheath 25 communicating with each other is provided between each divided body, which is tension-stopped using a lateral PC steel rod 23a, and a sealing material (not shown) is provided between the uneven connecting surfaces of each divided body. )
Insert and secure with bolt 27 and nut 27a. The press-fitting mechanism and the bottom plate 16 that have been removed are placed on the lower concrete block 21a placed and connected on the cutting edge block 14, and the pushing operation of each hydraulic jack 18 and the excavation and discharge of internal earth and sand are restarted to perform press-fitting. By repeating this process, a plurality of intermediate concrete blocks 21b and upper concrete blocks 21c are successively press-fitted and submerged. When press-fitting each concrete block 21, the gap 2 is filled with a hose 28 that is lowered from the ground to the outside bottom, or a hose 28 that is passed from the inside lower part of the lower concrete block 21a to the outside through the cross hole 29.
Bentonite mud water 30 is continuously forced into the interior of the wall 11a to prevent the earth wall 11a from collapsing and to reduce frictional resistance.

In addition, when the middle and upper concrete blocks are formed into vertically divided quarters like the lower concrete block 21a, the dividing positions are mutually shifted so that the joint surfaces 31 are staggered when viewed from the side, and the joint surfaces 31 cross each other. This prevents the caisson from weakening due to alignment of the joint surfaces.

The lower concrete block 21a has a starting/reaching tunnel entrance 32 which is temporarily closed on the longitudinal side facing each other either alone or across two lower concrete blocks 21a. The departure and arrival wellhead is the starting wellhead when it is the starting point for installing a propulsion pipe, and it is the arrival wellhead when receiving the propulsion pipe from another location.

The starting/reaching pit 32 has a ring part 32a on the inside, a rubber packing 32c fixed with bolts 32b on the inside of the ring part 32a, a steel part 32d with both ends buried in parallel on the outside surface, and welded to the outside surface of the steel part 32d. It consists of a closed-off plate 32e. Note that the ring part 3
2af As shown in Figure 7B, the thickness is increased by 32 for reinforcement.
Some have a'. Lower concrete block 2
When the parts from 1a to the upper concrete block 21c are press-fitted to a predetermined depth, the press-fitting mechanism such as the hydraulic jack 18 is removed, and after the inside of the cutting edge block 14 is leveled, crushed stone or the like is thrown in to form the filling layer 33. , and then connect the bottom slab concrete 34 to the recess 14e. 35 is a reinforcing bar, which is connected to the upper anchor bar by a coupler 26.

The temporarily blocked starting/reaching tunnel entrance 32 is made of steel material 3.
2d and the closing plate 32e are cut out in a circular shape to open them.

The upper concrete block 21c has a main pillar 36 removably attached to the upper surface, and an earth retaining plate 37.
is supported.

As described above, a caisson that enables the propulsion installation of the pipe culvert 38 is formed, so that in addition to the propulsion cutting port 38a, the pipe culvert 38 is sequentially carried in and propulsion installation is carried out from the starting shaft opening.

After the propulsion of the pipe 38 is completed, if necessary, reinforcing bars 35 are connected between the inner surfaces of the intermediate block 21b with the coupler 26, and the intermediate deck concrete with the amplifying section 43 is poured, and the upper amplifying section of the upper block 21c is placed. The top concrete slab 40 is placed on top of the concrete slab 44, and the manhole cylinder 41 is installed up to the ground surface.
2, the main pillar 36 and earth retaining plate 37 are extracted and removed while backfilling with earth and sand. In addition, the 10th
As shown in the figure, when the main pillar 36 is fastened with a horizontal bolt 45 and a nut 45a, removal becomes easier.

In this way, the present invention inserts four earth anchors deep into the soil from the four corner points, attaches a plurality of hydraulic jacks under the upper pressure plate that is fixed to the earth anchors, and connects the ground anchors at multiple points below the cutting edge block. Since the concrete blocks below the cutting edge block are held horizontally by multi-point pushing by each hydraulic jack and the excavation and removal of internal earth and sand, each concrete block below the cutting edge block is kept horizontal and efficiently press-fitted into the specified position in the soil. This produces the effect that it can be submerged.

When press-fitting and sinking a precast concrete multi-layer caisson as a base for laying propulsion pipes mainly for sewerage, the press-fitting and sinking work of the precast concrete multi-layer caisson was achieved by shortening the construction period and reducing construction costs. This produces the effect that it is possible to

[Brief explanation of the drawing]

Figure 1 is a longitudinal front view of the middle concrete block being press-fitted, Figure 2 is a plan view of the upper concrete block being press-fitted, Figure 3 is a partial front view of the same, and Figure 4 is a partial front view of the same. Figure 5 is a cross-sectional plan view of the lower half of the intermediate concrete block formed as a divided body;
Fig. 6 is an enlarged front view showing the starting/arrival tunnel entrance with a part of the blocking plate removed, Fig. 7A is a vertical sectional view of the same,
Figure 7B is a longitudinal sectional view of the same with the ring part thickened, Figure 8 is a partial view showing the connection state of the cutting edge block, lower concrete block and bottom slab concrete, Figure 9 is the intermediate concrete block and middle slab. Figure 10 is a partial view showing the connection of the upper concrete block, top concrete slab, and main column; Figure 11 is a longitudinal sectional view showing the state of the multilayer caisson press-fitted to a predetermined depth. , Figure 12 is a longitudinal front view showing the state in which the bottom slab concrete has been poured and the pipe is propelled and laid from the starting tunnel entrance, and Figure 13 is the middle slab concrete poured and the top concrete slab placed. Figure 14 is a longitudinal front view of the manhole cylinder installed and backfilled with earth and sand; Figure 14 is a longitudinal side view; 11 is the ground;
12 is an earth anchor, 13 is grout, 14 is a cutting edge block, 15 is an H-type steel for pressurization, 16 is a bottom plate, 17 is a lower pressure plate, 18 is a hydraulic jack, 1
9 is the upper pressure plate, 20 is the cone hydraulic chuck, 2
1 is a concrete block, 22 is a longitudinal sheath, 23 is a longitudinal PC steel bar, 23a is a lateral PC steel bar, 24 is a gap, 25 is a lateral sheath, 26 is a coupler, 27 is a bolt, 28 is a hose, 29 is a cross-hole, 30 is bentonite mud water, 31 is a joint surface, 32 is a starting/arrival wellhead, 33 is a filling layer, 34
is concrete bottom slab, 35 is reinforcing steel, 36 is main pillar,
37 is the earth retaining board, 38 is the pipe, 39 is the middle deck concrete, 40 is the top concrete block, 41 is the manhole cylinder, 42 is the step, 43 is the thickened part of the middle deck concrete, and 44 is the upper concrete block. The thickened portion 45 is a horizontal bolt.

Claims (1)

[Claims] 1. A lower concrete block divided vertically into multiple pieces, a plurality of intermediate concrete blocks, and an upper concrete block are sequentially placed and connected on the cutting edge block for the subcase, and the excavated soil on the inside and the excavation stabilizing liquid on the outside are placed. In the press-in method of burying a multi-layer caisson underground by injecting water and pressing while maintaining the horizontal position using multiple hydraulic jacks, the vertical joint surfaces of the upper, middle and lower concrete blocks are staggered. The cutter block is divided so as to be offset from each other, and a water-stopping rubber ring is fitted in the middle of the outer surface of the cutting edge block with a part thereof protruding, so that the injection of the drilling stabilizing liquid is received on the upper surface of the rubber ring; By releasing the temporarily closed part provided on the side wall of the lower concrete block, a starting and reaching entrance for the pipe is formed, and a removable main column for supporting the retaining plate is installed vertically on the peripheral wall of the upper concrete block. This method is characterized by the press-in and sinking of precast concrete multi-layer caissons as starting and reaching bases for propulsion pipes mainly for sewerage.